1. Field of the Invention
The invention relates to a heating, ventilation, and air conditioning (HVAC) system for a motor vehicle. More particularly it relates to a flat, modular HVAC system having minimal packaging requirements.
2. Prior Technology
During the design of a motor vehicle, the shape and dimensions of the vehicle body are defined. This determines the maximum amount of space available for each vehicle system and component to be installed. The result of this process, that often takes place parallel to the design and aerodynamic development of the vehicle, is often referred to as establishing the packaging requirements of components. The packaging requirements of HVAC systems, particularly air conditioning units, requires intensive development work because such equipment requires significant space.
Such development work is focused first on the geometry of the HVAC system (i.e. to make it smaller), and second on the position of the HVAC system within in the vehicle such that it does not interfere with the vehicle's passengers. As a result, the HVAC system may be placed, for example, in the instrument panel and/or front partition panel to maximize the foot space available to the driver and front seat passenger. Nevertheless, current HVAC systems still require excessive mounting space in a longitudinal direction of the vehicle, despite the optimized packaging and geometry.
In DE 100 42 683 A1 a known air conditioning unit is disclosed. The air conditioning unit has a first flat casing part extending in a first main extension plane, whereby the first flat casing part includes a fan and at least one directly downstream first flow channel section with an evaporator body arranged within. Further, a second flat casing part extending essentially in a second main extension plane is provided that includes a second flow channel section arranged downstream of the first flow channel section, with a heating body arranged in it as well as at least one downstream air outlet openings. This invention is characterized by the fact that the second flat casing part is connected to the first flat casing part forming an angle greater than 0° and smaller that 180° between both main extension planes.
Another air conditioning unit is described in U.S. Pat. No. 6,708,513. Here the air conditioning unit comprises a compressor with a compressor drive, an interior heat exchanger, an expansion element, an external heat exchanger and, if applicable, an internal heat exchanger. This unit is characterized by the fact that it is established as independent flat module, which is intended, in a cooling mode, to cool and, in a heat pump mode, to heat. The compressor is a high-power small-volume carbon dioxide compressor. The compressor drive is integrated into the module, with a power supply compatible with a single power source.